R(D(*)) Measurement at the Belle II Detector.

Date:

A talk given at the Canadian Association of Physicists Conference 2019.

Abstract: The Belle II detector is a significant upgrade of the Belle detector and will be a competitive, perhaps unique, environment in which to study rare B decays with missing energy to a sensitivity that would exhibit indirect New Physics effects. From a $B-\bar{B}$ meson pair that has been produced in the SuperKEKB energy-asysmmetric $e^+e^-$ collider and $B$-factory, one $B$ meson can be fully reconstructed through powerful $B$-tagging, which in turn provides strong constraints for the other $B$ meson. The design luminosity of SuperKEKB is $8\times10^{35}\,\mbox{cm}^2\,\mbox{s}^{-1}$, where the Belle II experiment aims to record $50\,\mbox{ab}^{-1}$ of data, a factor of 50 more than the original Belle experiment. This is an ideal environment in which rare decays with missing energy can be measured. The decay $B\rightarrow D^{(*)} \tau \nu$ will be examined with the prospects of the $R(D^{(*)})$ measurements, in which we anticipate a result of unprecedented precision with as little as $5\,\mbox{ab}^{-1}$ of data.